The present invention relates to a conjugate of protein labeled with a dye, its preparing method, and a sensor using the same.
Hitherto, the cyanine labeling dye having a highly reactive functional group has been often used in labeling of protein. In this case, the functional group of the labeling dye reacts with amino group or carboxyl group of protein, and about 20 to 50 molecules of labeling dye are bonded with one molecule of protein. Usually, protein contains hundreds to thousands of amino groups or carboxyl groups, but since the protein has a three-dimensional solid structure, only about 50 amino groups or carboxyl groups of them are estimated to participate in reaction. In the prior art, therefore, it was a limit to label one molecule of protein with about 50 molecules of dye.
It is hence an object of the invention (1) to enable to label with more dyes, (2) to apply labeled protein in immunochromatography utilizing antigen-antibody reaction, and (3) to obtain a sensor having an excellent sensitivity.